Investigating the Effect of Geometry and Compaction on Horizontal Shear Capacity along Asphalt Joints

Asphalt pavement joints are created when a new asphalt layer is placed and compacted next to an existing layer. However, poor interaction between the new and the existing layers can trigger premature failure at the pavement surface. One reason is that conventional methods for assessing and evaluating the mechanical capacity of asphalt joints are based mostly on volumetric measurements. This prevents engineers from estimating the impact of different construction techniques and methods on the mechanical key properties of asphalt joints, such as the shear capacity. This study examined how changes in the geometry of the joint interface and compaction patterns can improve the shear capacity of asphalt joints. Two new shear test methods were developed to investigate the shear capacity of laboratory-produced asphalt joints with different interface inclinations and compaction techniques. The results showed the capability of these new shear tests to determine the effect of selected key construction parameters on the quality of the joints. These findings provide valuable background for further field investigations, paving the way for constructing more-durable and -reliable asphalt pavement joints under real-world conditions.